uBlock/platform/mv3/scriptlets/no-xhr-if.js

/*******************************************************************************

    uBlock Origin - a browser extension to block requests.
    Copyright (C) 2019-present Raymond Hill

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see {http://www.gnu.org/licenses/}.

    Home: https://github.com/gorhill/uBlock

    The scriptlets below are meant to be injected only into a
    web page context.
*/

/* jshint esversion:11 */

'use strict';

/******************************************************************************/

/// name no-xhr-if

/******************************************************************************/

// Important!
// Isolate from global scope
(function uBOL_noXhrIf() {

/******************************************************************************/

// $rulesetId$

const argsList = self.$argsList$;

const hostnamesMap = new Map(self.$hostnamesMap$);

/******************************************************************************/

const scriptlet = (
    conditions = ''
) => {
    const xhrInstances = new WeakMap();
    const needles = [];
    for ( const condition of conditions.split(/\s+/) ) {
        if ( condition === '' ) { continue; }
        const pos = condition.indexOf(':');
        let key, value;
        if ( pos !== -1 ) {
            key = condition.slice(0, pos);
            value = condition.slice(pos + 1);
        } else {
            key = 'url';
            value = condition;
        }
        if ( value === '' ) {
            value = '^';
        } else if ( value.startsWith('/') && value.endsWith('/') ) {
            value = value.slice(1, -1);
        } else {
            value = value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
        }
        needles.push({ key, re: new RegExp(value) });
    }
    self.XMLHttpRequest = class extends self.XMLHttpRequest {
        open(...args) {
            const argNames = [ 'method', 'url' ];
            const haystack = new Map();
            for ( let i = 0; i < args.length && i < argNames.length; i++  ) {
                haystack.set(argNames[i], args[i]);
            }
            if ( haystack.size !== 0 ) {
                let matches = true;
                for ( const { key, re } of needles ) {
                    matches = re.test(haystack.get(key) || '');
                    if ( matches === false ) { break; }
                }
                if ( matches ) {
                    xhrInstances.set(this, haystack);
                }
            }
            return super.open(...args);
        }
        send(...args) {
            const haystack = xhrInstances.get(this);
            if ( haystack === undefined ) {
                return super.send(...args);
            }
            Object.defineProperties(this, {
                readyState: { value: 4, writable: false },
                response: { value: '', writable: false },
                responseText: { value: '', writable: false },
                responseURL: { value: haystack.get('url'), writable: false },
                responseXML: { value: '', writable: false },
                status: { value: 200, writable: false },
                statusText: { value: 'OK', writable: false },
            });
            this.dispatchEvent(new Event('readystatechange'));
            this.dispatchEvent(new Event('load'));
            this.dispatchEvent(new Event('loadend'));
        }
    };
};

/******************************************************************************/

let hn;
try { hn = document.location.hostname; } catch(ex) { }
while ( hn ) {
    if ( hostnamesMap.has(hn) ) {
        let argsIndices = hostnamesMap.get(hn);
        if ( typeof argsIndices === 'number' ) { argsIndices = [ argsIndices ]; }
        for ( const argsIndex of argsIndices ) {
            const details = argsList[argsIndex];
            if ( details.n && details.n.includes(hn) ) { continue; }
            try { scriptlet(...details.a); } catch(ex) {}
        }
    }
    if ( hn === '*' ) { break; }
    const pos = hn.indexOf('.');
    if ( pos !== -1 ) {
        hn = hn.slice(pos + 1);
    } else {
        hn = '*';
    }
}

argsList.length = 0;
hostnamesMap.clear();

/******************************************************************************/

})();

/******************************************************************************/